Film feeding device for projection apparatus



Oct. 3, 1939. H. o. HIRSCH FILI FEEDING DEVICE FOR PROJECTION APPARATUS Filed Nov. 21, 1938 Patented Oct. 3, 1939 UNITED STATES PATENT OFFICE 2,174,680 FILM FEEDING DEVICE FOR PROJECTION APPARATU Henry D. Chicago, 1]]. Application November 21, 1938, Serial No. 241,605 2 Claims. (Cl. sax-2a) This invention relates to improvements in film feeding devices for projection apparatus.

It m an object of the invention to provide a device by means of which a film carrying a Series of pictures may manually be fed longitudinally in either direction over any desired distance without requiring the operator to grip the film and to maintain it in its predetermined Path.

It is another object of the invention'to provide an attachment particularly suitable for photographic enlargers by means of which the film may be fed step by step to bring successive pictures on the film into proper position for enlar in and for retaining automatically the film in any position to which it has been set.

It is also an object of the invention to provide an attachment for confining a portion of the film during its movement within a certain rectilinear path in a single plane to facilitate and accelerate the movement of any desired picture on the film into the optical axis of the projection device and for retaining the film firmly in this adjusted position while the optical equipment of the projecting device may be adjusted to proper focus.

Another object of the invention is to provide an attachment in the form of a self-contained structure which can easily be united with or removed from a projection device, as for instance, a photographic enlarger, and which will permit selective intermittent feeding of the film without requiring the operator to grip or touch,

thefilm with his fingers, at the same time preventing the coils of the film from slipping in axial direction or uncoiling out of the film supports usually provided on enlargers.

With these and numerous other objects in view, an embodiment of the invention has been illustrated in the accompanying drawing to which reference is made in the following specification.

In the drawing:

Fig. 1 is a perspective view of the attachment in open condition Fig. 2 is on a larger scale a transverse section of the device inoperative condition, about on line 22 of Fig. 1;.

Fig. 3 shows a similar transverse section about on line H of Fig. 1;

Fig. 4 is adetail of the end'portion of the attachment, and

Fig. 5 shows the attachment in front elevation in combination with a photographic enlarger.

Fig. 6 shows perspectively another type of printing machine for photographic purposes.

In projection apparatus in which a photographic film is to irregular intervals, as con graphic apparatus, it has be advanced slowly and at trasted with cinematobeen customary to provide a film guideway within which the film is advanced while the optical equipment is spaced 5 from the film and to bring to operative condition after the optical equipment the film had temporarily been arrested in a position for projection.

The manipulation of the film by the fingers frequently proved injurious to the emulsion, par- 10 ticularly in making enlargements. The operator must necessarily put after its exposure into th the printing paper e various solutions required for development and fixation, and then must returnto the enlarger for selecting the next ll and a pair of film of the plate. Each film supports 2, one at each end support preferably is made up as an approximately tubular part, just and permit the film the support 2 to pa through a slot 3 onto the plate I.

- sufficiently long to hold the end coils of a film ss from the interior of In order to maintain the film F in proper alinement with the optical equipment, the plate is provided on its top surface with means engaging opposite longitudinal edges of. the film. These means are shown as a pair of shoulders 4 spaced g5 transversely a distance corresponding to the width of the film, whereby any lateral displacement of the film during its passage over the plate I is prevented. The plate also is provided in its central portion with an aperture in size and shape to the picture 5 corresponding area of any picture on the film. For the purpose of projecting any desired picture, the film is moved longitudinally until the desired the opening 5.

pic

ture is in registry with The film as used in modern miniature cameras is provided with longitudinal marginal portions p free of sensitized emulsion and in which sprocket holes 8 are provided for mittently through the sprocket holes 3 are utilized for feeding the film intercamera. The same intermittently feeding through the attachment of the present invention. Owing to the tudinal shoulders 4 on the provision of the longiguideway, the pictures on the film can properly becentered lengthwise and transversely with respect to the opening 5 in the plate I, permitting the projection of each picture in proper position after adjustment of. the film. v

The plate I in the form of a substantially fiat rigid strip of metal is connected with the neartubular supports 2 by pairs of brackets I, I which are secured by brazing, welding or the like to the supports 2 and which have fiat top surfaces on which the plate I rests. The plate may be detachably secured to these brackets by screws 9 or other fastening means. Hence, it is-feasible upon detachment of'the film coil supports 2 from the plate I to manually feed relatively short and approximately straight strips of film through the guideway in the usual manner.

In order to advance the film longitudinally through the guideway, the pair of brackets I connected with one of the film coil supports 2 serves as carrier for the film feeding means. As shown in Fig. 3, a shaft in the brackets 8, and is provided on an enlarged portion between the brackets with sprockets II. The sprockets are spaced axially on the shaft sufficiently to permit the teeth thereon to engage the sprocket holes s, and the teeth on the sprockets are circumferentially spaced in accordance with the longitudinal spacing of the sprocket holes in each series on the film. Shaft II is extended from one of these bearing brackets 8 outwardly and is provided at the projecting end with a knob [3.

The guide plate spaced from each other a distance equal to the spacing of the series of sprocket holes s on the. film, and the teeth on the sprockets I! are adapted to project through these holes ll to enter the sprocket holes, whereby upon rotation of the knob It, the film may be fed in either direction and adjusted until the selected picture thereon is in registry with the window or opening in the guideway, and all these operations can be carried out without the film itself being touched by hand.

The plate I is, furthermore, provided with longitudinal shallow shoulders l5 spaced transversely a distance equal to the width of the emulsion area of the film, so that the latter is frictionally supported only on the marginal zones p while it is being moved forward or backward. The shoulders l5 have a height approximately equal to the thickness of the film.

For the purpose of maintaining the film in close overlying relation to the top surface of the guideway during the during projection, the also a cover plate at one edge of plate I and longitudinal shoulders spacedill) from each other transversely a distance about equal to the width of the film. In order to place the film yieldingly flat against the top guideway, the cover It is provided with a plurality of strips I! of soft material, as velvet, or the like, engaging the top surface of the film when the cover is in closed position. An 20 size and shape to the picture it in a predetermined fixed relation with respect to the plate I when moved to closing position.

Thisrelationisde edbytheregistryof ments formed by plate It will then be in engagement with the II is rotatably supported I' has smaller apertures l4 vertical adjustment on an upright post II and adjusting movement or.

base-board surface of the J the projection work.

the opening it in the cover It with the opening 5 in the guide plate I. The marginal reinforceshoulders I! on the cover impart suilicient weight to the cover It to permit the same to drop to operative position, as shown in Fig. 2, after it has been swung in direction towards the guide plate beyond a right angle position thereto, and the lip 2| on the cover front edge of the guideway, thereby assuring the proper registry of the aperture 2| in the cover with the aperture 5 inthe guideway. Thisrelation also is assured by selecting a relatively long hinge II for pivotally connecting the cover plate ll with the guide plate I. The cover plate Ii, furthermore, is provided with smaller openings 22 of the through the sprocket holes s in the film to move longitudinally of the cover without exerting any lifting effect on the same.

The film asused in miniature cameras and the like is extremely smooth and very resilient, The coils of the film have a tendency to slip out of the supports 2 in which the coiled ends of the films rest. In order to prevent this movement at the coiled ends while at the same time permitting the film to be inserted into the attachment in a direction at right angle to the longitudinal axis of the same, the supports 2 are provided with gate bars 23 pivotally connected at 24 to the front edges of the supports and adapted to be swung to open position, as shown in dotted lines in Fig. 1, whereby the coil of the film may be placed into the respective support. slippage of the coils from the support is prevented by moving the gate bar a notch 25 also provided in the front edge of the support. At the opposite end of each support 2, a similar stop bar 26, not necessarily movable, may be located, whereby upon inserting the film coil from one end insertion of the film to excessive depth is preven The entire self-contained structure is particularly adapted for combination with an enlarger, as shown for instance in Fig. 5. The lamp housing 3. of the enlarger is usually supported for carries a movable condenser mount 12 at thelower end provided with means, for instance, in the form of a small lever or crank 33, for raising and lowering the condenser mount with respe t to a platform 34 also adiustably supported on the post II. This platform usually forms the top element of the lens mount ll in which the lens indicatedbyacarrierrink 3i inmjmaybeediusted to permit 31 to be sharply focussed thereon. The platform 34 on which the film travels in most enlargers terminates in arcuate strips of metal or coil holders ll in one of which the coil is podtionedln order topermitthefilmtobe gradually drawn into the other holder in accordance with It happen: very frequently that the coils slip from these era; the operator then has to straighten out the film again and begin the focusing operation tor manulens. This operation had hands which short time before had been used in various photographic solutions.

The self-contained structure forming the sub- 23 to full line position into the picture projected upon the 'lease oi the coils from the Ject matter of the present invention can easily be reinovably positioned on the platform 34 of any enlarger and will eliminate the necessity of touching the film during enlargement work and will at the same time prevent the accidental resupports at the end of the platform.

In the printing machine shown in Fig. 6, theattachment of the present invention may be positioned with its guideway insidethe housing 4| which forms the principal partof the machine.

In this type of machines the source of light is.

located in such manner as to illuminate the film which may be fed transversely of the housing 4| between glass plates, not illustrated, a transverse slit 42 extending for this purpose through the housing, Here also, as shown, the attachment can be inserted in this slit and the projection will furnish an image in the plane 43 in which in some suitable manner, as customary in machines of this character, the paper to be printed is positioned. Machines of this type are utilized for enlarging films of one certain size to furnish prints of another certain size.

I claim:

1. In a device of the character described, the combination of a guide plate for a picture film, the plate having an opening corresponding in size and shape to the size and shape of a picture on the film, means in the plate for maintaining the film in predetermined relation transversely on the plate, said means being adapted to engage longitudinal edges of a film on the plate, a cover plate hingedly connected with the guide plate and provided with an opening adapted to register with the opening in the guide plate when the cover is in closed position, means on the cover plate for yieldingly maintaining the film in opermount and the platform of ative position transversely of the plane of the guide plate and in engagement with the first mentioned means, and means on the cover plate foraligning it with the guide plate when moved to closing position said guide plate and cover plate forming a self-contained structure adapted to be removably inserted between the condenser mount and the platform of a projecting mechanism.

2. In combination with a guide plate for a picture film having an opening corresponding in size and shape to the size and shape of a picture on the film, longitudinally extending shoulders on said guide plate spaced from each other transversely a distance corresponding to-the width of ,the film, a cover plate, means for hingedly connecting said cover plate to said guide plate along a longitudinal edge of the guide plate, marginal longitudinal reinforcements on the cover plate adapted to constrain it for movement in a. certain direction from right angle position with respect to the guide plate, the cover plate being provided with an opening adapted to register with the opening in the guide plate when the cover plate is moved to closed position, and an overhanging angular projection on the cover plate extending from one of said reinforcements and adapted to engage irictionally the edge of the guide plate opposite that edge on which the hinge for the cover plate is secured, film pockets removably secured to the ends of the guide plate on the face opposite that on which the cover plate overlies the guide plate, said guide plate, cover plate and film pockets forming a self-contained structure with the cover plate and guide plate being adapted for insertion between the condenser a projecting HENRY D. Hmscrr.

mechanism. 

